1. Field of the Invention
This invention relates to the "laying" of end papers on the front and rear sides of inner books and, particularly, to the application of end papers to book blocks which are being continuously conveyed, with their spine sides facing downwardly, along a transport path. More specifically, the present invention is directed to apparatus for delivering end papers into registration with moving book blocks and, especially, to such apparatus having end paper guide channels extending along an inner book transport path and further having feeders for isolating end papers from stacks and delivering the thus isolated end papers into the guide channels such that, while moving parallel to the transport path, they are overtaken by the inner book to which they are to be applied. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
In the book binding art, and particularly in the manufacture of hard cover books, end papers are applied to the opposite sides of the "inner" books, i.e., bound book blocks which have been previously formed. These end papers are in the form of folded sheets which are adhesively bonded to the outermost sheets of the inner books.
Published German Patent Application 29 48 802 discloses a device for applying end papers to the first and last folded sheets of an inner book located in a transport channel of an adhesive binding machine. In this prior art apparatus, the end papers are isolated from a stack, by means of laterally positioned rotating feeders associated with a magazine and cooperating draw-off drums with grippers, and are fed to U-shaped channels arranged at a distance from the transport channel. The inner book and the end papers are subsequently simultaneously transported, respectively in the inner book channel and in the end paper channels, via fingers which are carried by a drive chain. The end papers are secured to the first and last sheets of the inner book, by means of an adhesive, in such a manner that a space or interval is usually provided between first edges of the end papers and the parallel edges of the inner book spine region. This interval is a function of the particular binding process being employed and is achieved by vertically offsetting the bases of the end paper channels relative to the base of the inner book transport channel.
A significant problem incident to the use of prior art devices of the type depicted in the above-referenced application is warping or buckling of the end papers. This warping or buckling results from the fact that the end papers will be at rest in their channels when contacted by the continuously moving fingers of the transport, i.e., the buckling or warping occurs as a consequence of the impact of the transport fingers on the trailing edges of the end papers.
A further deficiency of the above-described and other prior art apparatus resides in the fact that book through-put speed is limited by the time interval required to place new end papers in the channels after movement has been imparted to immediately preceding end papers. As should be obvious, new end papers cannot be delivered to the end paper channels until the previously delivered papers have been placed into motion and transported a distance greater than their width.
Machinery used in the manufacture of books must have sufficient flexibility so as to able to be adjusted to process books having different formats. The relatively large diameter of the draw-off drums required for end papers of books having a large format, in conjunction with the disposition of the rotating feeders and the end paper supply magazine above the end paper channels, inherently results in a relatively large dropping height for the end papers when books having a relatively small format are produced using the same equipment. This, in turn, leads to an essentially unchecked throwing of the small-format book end papers into the end paper channels, with concomitant misfeeds, as well as ergonomically unfavorable working conditions when laying the stack of end papers in the magazine.